When running Quick3D windows installer, it detects the registry key to find Qt 4.7.2, which is required:

HKEY_CURRENT_USER/Software/Trolltech/Versions/DefaultVersion

However, when user has other versions of Qt installed first, the default version sticks to the first version of Qt installed. In this case, it will fail:

1. User installed some other version, say 4.7.3 first
2. User installs 4.7.2
3. User install Quick3D, it will fail to detect Qt 4.7.2, because the registry key remains 4.7.3

Suggestion: Since all the Qt versions are listed as sub registry keys, the installer should detect sub keys for all the Qt versions installed, instead of the default Qt version installed.

Originally from Internal Jira: QT-5013